Loctite Threadlocker Blue 242 Vs Red 271

The adhesion strength of the Blue Loctite threadlocker is rated modest. It can be disassembled with a lot of torque, but specific chemicals and/or heat make it simpler. It comes in tape, semisolid, and liquid forms, and it cures in 24 hours if applied to the threads. Loctite 242, Loctite 243, and Loctite 248 are the most common types.

The adhesion strength of the Red Loctite threadlocker is regarded to be strong. After the Red Loctite threadlocker has been applied, it cannot be removed by merely applying torque; it takes specific heat in conjunction with torque (or special chemicals) to dismantle the components.

It comes in a semisolid anaerobic or liquid form, and it cures in 24 hours after being applied to the threads. Loctite 262, Loctite 268, Loctite 271, and Loctite 272 are common variations.

In comparison to the Blue threadlocker, the Red threadlocker is a more permanent option that has extra strength, durability, and support for thread and metal fastener sizes.

Comparison Table

CharacteristicsLoctite Threadlocker Blue 242Loctite Threadlocker Red 271
BaseDimethyl acrylate esterDimethyl acrylate ester
Specific gravity1.11.10
VOC Content6.17 g/l7.81 g/l
Application Temperature10°C10°C
Service Temperature-65°F (-54°C) to 300°F (149°C)-65°F (-54°C) to 300°F (149°C)
Flash Point>199.9°F (93°C)>199.9°F (93°C)
Viscosity900 – 1,400 cP400-600 cP
Moisture resistantYesYes
Set Time10 minutes10 minutes
Cure Time24 hours24 hours
Cured FormNon-flammable, hard solidNon-flammable, hard solid
Size6 ml6 ml
Shelf life24 months24 months

Strength Comparison

The strength of a threadlocker determines how easily it may be removed. Threadlockers of low and medium strength may be removed using common hand tools. High or long-term strength disassembly of threadlockers may need the use of direct, strong heat.

Although Red threadlockers can totally seal the assemblies, there are some situations when permanency isn’t necessary or even harmful.

Disassembling components for maintenance and repairs typically necessitates the removal of threadlockers. Medium-strength Blue threadlockers are the ideal choice for assemblies that require frequent maintenance and repair.

Evaluation of Heat Endurance

One of the most important elements that might affect the security and effectiveness of any fastener is heat. Using a product that is meant to endure harsh climatic conditions, such as high temperatures, reduces the risk of thread loosening.

Threadlockers in Red and Blue offer a temperature range of -65°F to 300°F (-54°C to 149°C), making them appropriate for a wide range of applications.

These threadlockers, on the other hand, will not work in high temperatures such as 650°F (343°C).


Threaded assemblies are subjected to vibration and torque in almost all applications, from heavy machinery to automobile assembly.

Red threadlockers are recommended for applications where there is a significant danger of vibration or shock. These thread-locking adhesives are the strongest and give the most resistance to vibration, shock, and torque. As a long-term solution, they remain securely in place.

A medium-strength Blue threadlocker, on the other hand, is an excellent all-around answer for sealing and securing assemblies, but it can’t match its companion in terms of shock and vibration dampening.


Since both are liquid formulas, their expertise lies in the everyday assemblies. Their viscosities are ideal for locking fine threads and blind holes. The higher viscosity gives Blue 242 an advantage over its rival Red 271 regarding the viscosity comparison.

Assembly Classification

The majority of threadlockers are made to be utilized in fasteners just where they’re needed. The glue is applied to the thread shortly before the fastener is fastened in these circumstances, securing it in place. This is perfect for use in machine manufacture and maintenance.

You may select a medium-strength Blue threadlocker for maintenance and a high-strength Red threadlocker for production assemblies.

Thread Size

You must examine the thread size before selecting your best threadlocker. If you make a mistake, service or disassembly will be more difficult. Using a high-strength threadlocker in lower thread sizes might make removing the fastener without breaking the screw more difficult. Using a low-strength threadlocker on higher thread size, on the other hand, might limit the adhesive’s efficacy.

Generally speaking, the stronger your threadlocker has to be, the bigger your thread.

Fasteners with a maximum thread size of M18 are sealed and secured with Blue 242.

Red 271 is suitable for applications with thread sizes up to M20.

Metal Fasteners Size

Both of these threadlockers are used to secure metal fasteners in several applications, however, their compatible sizes are limited as listed below.

Metal fasteners of a diameter of 1/4″ (6 mm) to 3/4″ (19 mm) can be utilized with Blue 242.

Red 271 can be used on metal fasteners with a diameter of up to 1″ (25mm).

Application Area

  • For Blue 242:

Automotive – Valve covers, water pumps, alternators, oil pans

Maintenance – Light machinery, light conveyors, door hardware, tow motors

Home – Lawnmowers, grills, locksets, bicycles

  • For Red 271:

Automotive – Internal engine, auto frame, auto suspension, wheel studs

Maintenance – Heavy machinery, structural fasteners, heavy conveyors, material movers

Home – Structural bolts, handrails, playsets, H.D. equipment

Method of Application

Both Blue 242 and Red 271 have the same method of application for different appliances.

  • For Thru Holes:

Apply a few drops of the product to the bolt at the nut contact region

  • For Blind Holes:

Several drops of the substance should be applied down the internal threads to the hole’s bottom.

  • For Sealing Applications:

Apply a 360° bead of product to the male fitting’s leading threads, leaving the first thread unaffected. To completely fill the spaces, force the substance into the threads. Adjust product quantity as needed for larger threads and voids and apply a 360° bead of product to the female threads as well. Assemble the pieces and tighten them as needed. It takes around 10 minutes to set and 24 hours to fully cure.

Tools Required to remove a threadlocker

  • Utility knife
  • Damp cloth
  • A blowtorch
  • Heat-resistant safety gloves
  • Safety glasses
  • A wrench


With a moist cloth, wipe away any sticky residue right away. A combination of soaking in methylene chloride and mechanical abrasion, such as with a wire brush, can be used to remove the cured product.


Shear using basic hand tools and remove with methylene chloride for disassembly. Apply targeted heat to the nut or bolt to around 482°F (250°C) in rare cases where hand tools fail due to high engagement length. While the item is still hot, disassemble it.


  • Not for use on plastic parts, especially thermoplastics, where stress cracking of the plastic may occur.
  • It should not be used in pure oxygen or oxygen-rich environments, and it should not be chosen as a replacement.
  • Chlorine or other strong oxidizing compounds sealant
  • If you’re using two inactive metals, you’ll need to apply a primer.
  • Not for use in applications that need “food safe” fastener locking and sealing.

Quick Summary

  • Blue 242 is a medium-strength threadlocker while Red 271is categorized as a high-strength threadlocker.
  • Both can endure an equal amount of heat.
  • Red 271 is highly durable as it can greatly resist shocks and vibrations.
  • The viscosity of Blue 242 is higher than its peer.
  • Blue 242 is ideal for high maintenance assemblies while Red 271 is recommended for manufacturing assemblies where high quality is needed.
  • Red 271 can support threads up to a greater size than its competitor.
  • Similarly, Red 271 can also support a higher size range of metal fasteners.
  • Both have equally plentiful areas of applications.
  • Both are easy to apply and remove.
  • These threadlockers are likewise limited.
  • Blue 242 has a slight economical edge over its competitor.